Tiltable mounting structure for coal cutting machines



Maly ll, 1954 c. F. osGooD TILTABLE MOUNTING STRUCTURE Foa coAL CUTTING MACHINES original med'June 19, 194s s sheets-sheet 1 ,W al n m l.

May 11, 1954 c. F. osGooD 2,678,204

TILTABLE MOUNTING STRUCTURE FOR COAL CUTTING MACHINES 5 Sheets-Sheet 2 Original Filed June 19, 1945 May 11, 1954 c.. F. osscon 2,678,204

TILTABLE MOUNTING STRUCTURE FOR COAL CUTTING- MACHINES Original Filed June 19, 1945 3 Sheets-Sheet .'5

`r M' 3 I 4 vvness of the oor.

Patented May l1, 1954 TILTABLE MOUNTING STRUCTURE FOR COAL CUTTING MACHINES (-lharles F. Osgood, Franklin, Pa., assignor to Joy Manufacturing Company,

" Pennsylvania a corporation of -Continuation of application Serial No. 600,299, VJune19,v 1945. rThis application July 17, 1950,

L Serial No..174,190

' This invention relates to miningV machines and l more particularly to an improved tilting arrange- =ment for a shortwall coal cutting machine.

During the cutting of coal with-a shortwall coal cutting machine there is a tendency of the cutter bar working up ordown in the coal due to "the unevenness of the mine floor, and it is neces- V'sary frequently to jack up or pry up with pinch `bars the machine to tilt the same either sidewise or endwise to compensate for the uneven- Usually, when it is desired to tilt the machine, the latter is jacked up by extraneous oor jacks while the machine remains lin a stationary-position with respect to the coal face. erated tilting shoes or skids vhave been recessed within the bottom of the machine-but such shoes In certain'instances, however, hand opor skids are limited'in action and due to their Arelatively small surface area tend tov sink into a `soft bottom; andftheir receiving recesses tend to become clogged or jammed with cuttings and dirt rendering them relatively impractical under vmost mining* conditions.

desirable vin a shortwall coal cuttingmachine to v It is, however, highly provide a built-in tiltingA arrangement which enables tilting of the machine in' anydesired direction as the machine is` fed over the' mine '.oor during thecutting operationand without vthe possibility; of sinking into a` soft bottom. or `jamming or clogging. Such a tilting arrangement must. not increase the height or the overall dimensions of the machine and must not be iunduly complicated.

' object is toV provide an improved tilting arrangement for a shortwall coal cutting Vmachine which v"avoids theuse of separate shoes'or skids recessed rwithin the machine bottom. .1A further, object is 'nto provide an improved skidarrangement which is built into. the bottom ofthe .machine whereby `Jthe possibility of clogging or jamming as is often `Aencountered in previous devices is avoided. Yet another object is to` provide an improved tilting arrangement for a shortwall coal cutting machine wherein the bottomskid of the machine is made `separate from vthe'rnachine frame and tilting devices are arranged betweenV the skid and the frame whereby the' frame may be tilted' relative v to the skid while the latter remains in firm supv ported contact with" the -floor ofv the` mine. still "further -objectis to-'provide anl improved tilting arrangement fora shortwallI 'coal' cutting-f the floor type.

machine wherein the bottom skid and mainframe cooperate to provide a cuttings chamber extending through the bottom of the machine through which the cuttings aremoved by the cutter chain whereby cuttings discharge occurs at the rear end of the machine remote from the coal face.

-Another object is to provide an improved tilting arrangement of the'iuid operated type whereby the coal cutting machine may be tilted sidewise or endwise with comparative ease. A further object is to provide an improved adjustable supporting structure for a coal-cutting machine of These and other objects and advantages of the invention will, however, hereinafter more fully appear.

This application is a continuation of my copending application Serial No. 600,299, led June 19, 1945, now abandoned.

In the accompanying drawings there are shown for purposes of illustration one form and -several modifications which the inventionmay assume in practice.

In these drawings:

Fig; 1 is a plan view of-a coal cutting machine with which a preferred illustrative embodiment of the `invention is associated.

Fig. 2 is a side elevational view of the coal cutting'machine shown in Fig. l.

Fig. 3 isan enlarged cross-sectional view taken substantially on lines'3-3 of Fig. 2, showing the rear jacks.

Fig. 4 is an enlarged cross-sectional view taken substantially on line 4 4` of Fig. 2, showing the front jacks.

Fig. 5 is an enlarged view.v in longitudinalV vertical section taken substantially on line 5 5 of Fig. 1.

Fig. 6 is a side elevational view showing the machine in tilted position with the cutter bar inclined downwardly.

Fig. 7 is a view similar to Fig. 6, showing the machine in tilted; position with .the cutter bar inclined. upwardly.

.Fig 8 is a front end elevational view ofthe coal cutting machine, showing the lmachine tilted about a longitudinal axis withV thecutter bar inclined edgewise.

Fig. 9 is a diagrammatical view illustrating the hydraulic system.

Fig. 10 .is a detail vertical. sectional view, with parts in full, showing a modified arrangement of one of the rear guide sheaves.

Fig. 11 is a detail vertical sectional view, with parts in full, showing a further modied jack construction.

Fig. 12 is a detail horizontal sectional view, with parts in plan, showing a modiiied mounting for a front guide sheave.

Fig. 13 is a detail vertical sectional View illustrating a modied form of jack mounting.

In this illustrative construction the improved adjustable supporting structure or tilting arrangement is shown associated with a coal cutfting machine of the shortwall type which may bev frame beneath the latter and has guided thereon an endless cutter chain 6.

Vsuspended beneath the bottom of the machine The cutter bar is frame by a hanger l preferably formed integral with the frame bottom. The motor 2 has its power shaft connected through spur gears 8, 9

and bevel gears Ill, i I tc a vertical shaft I2 suitably journaled within the rearward portion of the machine frame (Fig. The shaft I2 has Y secured thereto and drives a chain sprocket I3 arranged beneath the machine frame for driving the cutter chain 6. The feeding and controlling drums are arranged at the opposite sides of the machine frame and are connectable in driven relation with the motor through gearing fully described in the above mentioned patent whereby the` drums may be independently rotated in winding direction at either low or high speeds under the control of suitable clutches. The

`feeding and controlling drums 4 and 5 have respectively wound thereon feeding and controlling cables I4 and I5, and journaled on the rear end of the machine frame are pairs of rear guide sheaves IS and I1 and an intermediate guide sheave I8, while arranged at the forward end of the machine frame are guide sheaves I9, and the cables are adapted to be extended in various -manners around these guide sheaves during maneuvering and feeding of the machine as is well understood by those skilled in the art.

Now referring to the improved adjustable supporting structure or tilting arrangement whereby the cutter bar may be tilted about transverse and longitudinal axes to change its angle in altitude, it will be noted that underlying the machine frame is a bottom skid 2| on which the machine frame is supported by a plurality, herein preferably four, of hydraulic power jacks designated 22, 23, 24 and 25 arranged near the four corners of the machine frame and skid. The rear jacks 22 and 23 comprise cylinders 25 mounted in bores 2'! formed in projections 28 integral with the machine frame, and flanges 28 are secured as by bolts to the upper surfaces of the projections 28 in the manner shown. The front jacks 24 and 25 each comprise, as shown in Fig. 4, a cylinder 30 arranged beneath the projecting sides of the motor 2 and having upper flanges 3l secured as by screws to the bottom surfaces 32 of the motor projections. The cylinders of the four jacks contain pistons 33 having piston rods 34 extending downwardly through the lower heads 35 of the jack cylinders. These piston rods have secured to their bottom extremities oblate feet 36 seated loosely in sockets 31 formed in socketed members 38 secured to lugs or brackets 39 projecting laterally from the sides of the bottom skid 2l. The bottom surfaces of these skid brackets 39 are upwardly and outwardly inclined at 40 to facilitate lateral sliding movement of the skid over the mine floor. lf desired the jacks may be mounted in the manner shown in Fig. 13 with the lateral lugs or brackets 39 located near the tops of the sides of the bottom skid, and the jack cylinders in elevated positions at the sides ofthe machine frame. These four hydraulic jacks 22, 23, 24 and 25 may be operated in such manner as to tilt the machine frame sidewise about a longitudinal axis at either side of the bottom skid or to tilt the machine frame either upwardly or downwardly longitudinally about transverse axes, thereby to change the angle in altitude of the cutter bar as will later be fully explained. The oblate feet 36 loosely received in the sockets 31 of the bottom skid are free to move slightly sidewise to compensate for the tilting of the jacks with the machine frame with respect to the bottom skid. In this improved construction the machine frame has parallel depending flanges or vertical projections 42, 42 along its bottom spaced equidistantly from the longitudinal vertical center of the machine frame as clearly shown in Fig. 4, and these flanges cooperate with and overlap parallel upstanding flanges or projections 43, 43 on the bottom skid with the frame-flanges 43 arranged laterally outside of the skid-flanges 42. These overlapping anges 42, 43 cooperate with the machine frame and bottom skid to provide a horizontal chamber 44 extendingl longitudinally through the bottom portion of the machine. The rearward portion of the cutter bar 3 is arranged in this chamber and the cuttings brought back from the kerf by the cutter chain 6 are carried rearwardly through this chamber to discharge at the rear end of the machine remote from the projecting end of the cutter bar. The cooperating flanges 42, 43 on the machine frame and bottom skid are so arranged and constructed that the cuttings are coniined in the chamber 44 irrespective of the tilted position of the machine frame with respect to the bottom skid.

Again referring to the guide sheave arrangement, it will be noted that the pairs of rear guide sheaves I6 and I1 are journaled on upstanding axes on the frame projections 28, and the rear jacks 22 and 23 are arranged at the rear corners of the machine frame forwardly of the rearward and inwardly of the outer sheaves of each pair as shown in Fig. l, and the jacks are desirably located rearwardly of the feeding and controlling drums 4 and 5. The front guide sheaves I9 are herein mounted on swing arms 46 which straddle the front jacks 24 and 25 and have spaced lugs 41 pivotally mounted on bolts 48 supported by lugs 49 integral with the machine frame. Thus, the swing arms 46 may swing in a vertical direction about axes extending longitudinally of the machine frame to vary the angle of the front guide sheaves. By arranging the swing arms so that they straddle the front jacks, it is possible to locate these jacks near the front corners of the machine frame in the manner shown. The sheaves I9 arepreferably arranged in an inclined position so that the cables may be extended forwardly from the bottoms of the drums around these sheaves as desired. In the modification shown in Fig. 10, one of each pair of rear sheaves I6 and I1 surrounds the cylinder 26' of each of the rear jacks. Each gral with the machine frame.

jack cylinder supports a bearing 5I onwhich the sheave `is journaled,` and a collar -52'secured by-a set screw 53 to the upper portion of 'the jack cylinder retains the guide sheave in position at the upper surface of the frame projection 28'.. By arranging certain of the guide sheaves coaxial with the jack cylinders, extreme simplicity and compactness are attained. In like manner, the front guide sheaves I9 may be mounted in coaxial relation with the cylinders of the Vfront jacks, although with such an arrangement, the pivoted swing arm mounting for the sheavesimust be omitted. In the modification shown in Fig. 1l, conventional hand voperated jacks 55 have been substituted for the four-power jacks Aat the four corners of the machine frame, and these hand jacks are inverted and rest on the bottom skid 2|. extending upwardly through the 'to-p cylinder heads 5'! and the upper ends of the piston rods have oblate portions 5S loosely arranged in a sooketed member 59 attached to a lug 65 inte- Each hand jack has a conventional built-in pump 'di operated by a hand lever 52. In the modification shown in Fig. 12, the front guide sheave I9 is mounted on a horizontally swingable arm Si? pivotally mounted at 64 on the cylinders of the front jacks 24, 25. When these sheaves are in the full line position shown in Fig. l2, lugs 55 on the arms t shown in Fig. l2 with the swing arm against,

the side of the machine frame.

Now referring to the hydraulic system for supplying liquid under pressure to the cylinders of the power jacks 22, 23, 2A 'and 25, it will be noted that arranged within the frame of the machine is a conventional pump 6l' having its power shaft 68 driven by a spur gear 59 meshing with the motor shaft gear 8. The pump 6'! is preferably arranged within a liquid tank vIii having a suitableiiller plug 1I. As shown .diagrammatically in Fig. 9, the pump has its intake conduit 'I2 connected to the tank le, and the pump discharge conduit 'i3 is connected to the supplypassage of a Valve box 'Hi herein conveniently located at the rear end of the machine frame. The pressure conduit 'I3 is connectible through a relief valve 'I5 and conduit 'iGback to the tank lil. The exhaust passage of the valve box i4 is connected through a return conduit T back to the tank. i

The valve box 'it has bores containing four iconventional slide valves i8, 19, Sli and 8| (shown diagrammatically in Fig. 9) provided with operating levers 82. The valve box is connected through conduits 83, 84, 85 and 85 to the upper ends of the cylinders or the four hydraulic jacks. By suitably manipulating the levers for the valves 18, 79, Si) and 8i, liquid under 4pressure may be supplied to the jack cylinders as desired either in pairs or concurrently so that the pairs or" `side jacks may be selectively operated to tilt the machine frame in one `direction or the other Iabout a longitudinal axis, or the pairs o end jacks may be selectively operated to tilt the machine frame in eitherY direction about a transverse axis as desired. By operating the four jacks concurrently the machine frame may be elevated while the cutter bar is maintained in substantially horizontal position.

. The vgeneralrnode 'of :operation of the improved The jack pistons have piston rods 56 vand controlling cables I4 and I5 may be extended from their respective drums around certain oi? the guide sheaves as shown in Fig. 1, and laterally from the machine to suitable anchor jacks located at the ribs of the mine room. The drums may' be operated and controlled in the manner fully described in the .patent labove referred to so that the cutter bar may be sumped beneath the coal at one rib, then fed transversely across the coal face, and thereafter withdrawn from the face at the opposite rib all in the manner well known to those skilled in the art. By reversing the motor, rewinding the cables on .the drums, reversing the pump connections, andreversing the cutter bits on the cutter chain, vthe machine may operate in the reverse direction. During either direction of cutting, the slide Valves 78, 79, -89 and 2| controlling the hydraulic power jacks 22, 23, 24 and 25 may be operated to eiect tilting of the machine frame about transverse and longitudinal axes to'vary the angle in'altitude ot the cutter bar, thereby to facilitate the cutting functions. For example, two of the jacks at one side of the machine frame may be concurrently operated to tilt the machine frame about a longitudinal axis at the opposite side of the skid and, in like manner, the two jacks at the opposite side of the .machine frame may be concurrently operated to tilt the machine frame about a longitudinal in theopposite direction. Thus, the cutter bar maybe tilted in either direction about parallel longitudinal axes to effect edgewise tilting of the cutter Vbar as shown in Fig. 'i'. The pair of jacks at the rear end of the machine frame may be concurrently operated to raise the rear end of the machine frame to tilt the cutter bar about a transverse aXis located at the Vfront end of the bottom skid to tilt the cutter .bar downwardly as shown in Fig. 6. The front jacks may be concurrently operated to raise the front end of the machine frame to tilt the cutter bar upwardly, as shown in Fig. 7,

yabout a transverse' aXisy located at the rear end of the bottom' skid. And all four jacks may be concurrently operated to elevate the machine frame to locate the cutter bar in a horizontal position some distance above the licor level. When hand operated hydraulic jacks such as shown in Fig. 1l are .employed instead of the Ypower jacks,- tilting of the machine may be eiiected as desired simply by `operating the pumps of the jacksV either separately or in ,pairs in an obvious manner.

As a result.. of this invention, an improved adjustable .supporting structure or tilting arrangement is provided for a standard shortwall coal cutter whereby, without raising the machine bottom from .the mine floor, `the machine frame may be tilted about transverse and longitudinal axes to 'change .the angle in altitude of the cutter'bar. By lbuilding the hydraulic jack mechanism into a standard shortwall coal cutting machine, the `cutter bar may be tilted at will about r transverse and longitudinal axes while the cuttings brought back `from the kerf by the cutter'. chain are moved through the bottom of the machine to discharge at the rear end of the machine. By incorporating, the jack mechanism within the bottom skid structure of a shortwall machine, it :is possible to tilt the cutter bar Without the use oi extraneous jacks or skids. The improved adjustable skid mounting for a standard shortwall .coal 'cutting machine enables ,the cutter bar to Vbe tilted; as desired without inter-'1 rupting the feeding movement of the machine and while the cuttings are moved by the cutter chain through the bottom of the machine to discharge at the rear end of the machine irrespective o the tilted position of the cutter bar. The improved skid structure eliminates the need of separate tilting shoes recessed within the machine bottom as in previous known devices so that sinking into a soft bottom and the clogging of the skids and shoes, due to dirt and cuttings getting into their receiving recesses, is avoided. By the provision of the improved built-in, power operated jack structure for a standard shortwall floor cutter, the tedious and time-consuming task of jacking up the machine at frequent intervals during the cutting operation by means of extraneous jack devices or pinch bars is wholly avoided, a decided advantage in mines having low headroom. Other uses and advantages of the improved adjustable supporting structure or tilting arrangement will be clearly apparent to those skilled in the art.

While there are in this application speciiically described one form and several modiiications which the invention may assume in practice, it will be understood that this form and several modications of the same are shown for purposes of illustration and that the invention may be further modied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In a shortwall coal cutting machine of the door type, a bottom skid slidable over the floor of a mine and constituting the machine bottom, a machine frame mounted on said skid in overlying relation with respect thereto and having a horizontal open bottom in substantial parallelism with the skid bottom when said frame is in lowered position on said skid, said skid and said frame having cooperating side portions arranged in overlapping relation, a horizontal plane cutter bar secured to the frame bottom and projecting horizontally from said frame lengthwise thereof above the skid bottom when said frame bottom and said skid are in parallelism, a cutter chain guided for circulation about the margin of said cutter bar, said skid and the lower portion of said machine frame in all adjusted positions of the latter with respect to said skid cooperating to provide a horizontal chamber between said skid and the bottom of said frame just above the floor level and in 'which the rearward portion of said cutter chain is arranged, said cutter chain as it circulates during the kerf cutting operation moving the cuttings created thereby rearwardly in said chamber to discharge near the oor level at the rear end of the machine, said skid and said frame with their cooperating and overlapping side portions conning said "cuttings in said chamber as they are moved longitudinally rearwardly therethrough irrespective of the tilted position of said frame with respect to said skid. and means for pivotally mounting said frame on said skid and for tilting said frame and said cutter bar about a generally horizontal axis comprising extensible tilting devices arranged between said skid and said frame for exerting on the latter an upwardly directed force for tilting said frame and said cutter bar in a vertical direction about said axis relative to said skid to change the angle of the cutter bar with respect to the horizontal.

2. In a shortwall coal cutting machine of the door type, the combination comprising a bottom skid slidable over the floor of a mine and constituting the machine bottom, a machine frame overlying said skid and having a horizontal open bottom spaced above the skid bottom in substantial parallelism therewith when said frame is in lowered position on said skid, an elongated horizontal plane cutter bar supported by said machine frame and rigidly secured to said frame bottom and extending horizontally lengthwise thereof below the bottom of said frame in the space between the latter and the skid bottom when said frame and said skid are in parallelism, a cutter chain guided for circulation about the margin of said cutter bar for cutting a horizontal kerf substantially at the iioor level and for moving the cuttings created thereby during the cutting operation rearwardly in the space between the frame bottom and the skid bottom to discharge near the floor level at the rear end of the machine, and adjustable supporting mechanism between said skid and said machine frame for supporting the latter above the skid bottom and for tilting said frame and said cutter bar about a generally horizontal agis comprising adjustable tilting devices arranged between said skid and said frame for exerting on the latter an upwardly directed force for tilting said frame and said cutter bar in a vertical direction about said axis relative to said skid to change the angle of the cutter bar with resepct to the horizontal, said bottom skid and said machine frame having cooperating side closure portions whereby the cuttings are confined in the space therebetween during the movement of the cuttings rearwardly therethrough to discharge at the rear end of the machine irrespective of the tilted position of the machine frame with respect to the bottom skid.

3. A coal mining machine comprising, in combination, a bottom skid, a machine frame mounted on and overlying said skid, adjustable jack devices connected between said skid and said frame for tilting the latter relative to said skid, a cutter bar secured to the bottom ci said irai le and projecting forwardly from said frame, said skid and said frame having side closure portions cooperating to provide side closures thereby to form a substantially closed wall chamber extending lengthwise through the bottom of the machine and in which the rearward portion of said cutter bar is arranged, an endless cutter guided for circulation in an orbital path about the margin of said cutter bar, and a motor carried by said tiltable frame for driving said cutter chain, said cooperating portions of said skid and said frame providing said side closures for said chamber irrespective of the tilted position of said frame relative to said skid whereby said cutter chain may move the cuttings created during the cutting operation rearwardly through said chamber to discharge at the rear end of the machine, and means for adjusting said jack devices to exert upwardly directed forces on said frame to tilt the latter relative to said skid to vary the inclination of Said cutter bar with respect to the horizontal.

4. In a coal mining machine, the combination comprising a bottom skid slidable over the rioor of a mine, a machine :frame overlying and mounted on said skid, a cutter bar secured to the bottom of said frame between the latter and said skid and extending forwardly lengthwise of the machine, an endless cutter chain guided for circulation about the margin of said cutter bar, a motor carried by said trame for driving said cutter chain to move the latter in an orbital path,

said-skid' and said frame having side portionscooperating with the'bottoms of said skid andf'ramet'o `provide a chamber extending lengthwise throughout the bottom of the machine; and inwhichv said cutter chain moves orbita-ily to con-- vey the cuttings created during the cutting opera-V tion rearwardly through said cham-ber todis--Y charge at the rear end of the machine, and four independently/'operable hydraulic jacks arranged at the four corners. offsaid framebetween the latter and said skid for exerting upwardly directed forces on said frameto tilt saidframe relative to said skid to vary theinclination of said cutter bar with respect to.y the horizontal, andjsaid cooperating portions or said skid and saidlframe retaining the Ycuttings -in said; cham.- ber during. movement of the cuttings lengthwise tI-irough said chamber irrespective of the tilted position of said frame relative to said skid.

5. In a. shortwall coal cutting machine ofy the floor. type,k a bottom skid slidable over the iioor. of amine and constituting the machine bottom, a machine frame mounted on said skid in overlying relation with respect-I thereto and having a horizontal open bottom in substantial parallelism withthe skid bottom when said frame is in lowered'lhorizontal position on saidslrid, a horizontal plane cutter bar secured to the frame--bottom and projecting horizontally from said .frame lengthwise thereof'above the skid bottom close to the latter when said frame is in said lowered horizontal position, a cutter chain guided for circulation in an orbital path about the margin of said cutter bar for cutting a horizontal kerf near the floor level, said skid and the lower portion of said machine frame having side closure portions which cooperate in all adjusted positions of said frame with respect to said skid to provide a substantially closed wall horizontal chamber extending lengthwise of the machine between said skid and the frame bottom just above the floor level and in which the rearward portion of said cutter chain is arranged, said cutter chain as it circulates during the kerf cutting operation moving the cuttings created thereby rearwardly in said chamber to discharge near the floor level at the rear end of the machine, and means for pivotally mounting said frame on said skidand for tilting said frame and said cutter bar about a generally horizontal axis comprising extensible Y 10i ingsaid:v cutter chain*l` four "hydraulic jacks-one at each ofthefour corners ofthemac'hine frame and' arranged betweenv said skid and said framefor exerting upwardly directed forcesv on said'V fra-me to tilt the latter relative to said skid to vary thev inclination of said cutter bar with respect tothehori'zontal', said cooperating portions of said skid and said frame providing said side closures -for'said chamber irrespective oi the-tilted position of said framerelative to said skid where-v byt the'-cuttingsare-eonfined lforl rearward movement withinA sa-id chamber to discharge at the rear rend of the machine, a pump on said frame and drivenI bysaid motor, a liquid reservoir on said frame with which the suction `side of said ,said valvemeans back to'said reservoir. vl7f. Infla shortwall coa-l cutting machine ofthe type slidable on itsV bottom over the floor of a mine during its opera-tion, the combination com` ,prising-V a bottom skid constituting the machine bottom, a machine fra-me mounted on said skidV `I. inv overlying relation withwrespect `thereto and' tilting devices arranged between said skid and l 5. In a coal mining machine, a bottom skid having a horizontal open bottom in substantial parallelism with the skid bottom when said frame is in lowered horizontal position on said skid, a horizontal plane cutter bar secured to the frame bottom and projecting horizontally from said frame lengthwise thereof above the skid bottom close to the latter when said frame is in said lowered horizontal position, a cutter chain guided for circulation in an orbital path about the margin of said cutter bar for cutting a horizontal kerf near the floor level, said skid and said frame having side wall portions cooperating in all adjusted positions of said frame with respect to said skid to provide a horizontal substantially closed wall chamber extending lengthwise of the machine between said skid bottom and said frame bottom just above the oor level and in which the rearward portion of said cutter chain is arranged, said cutter chain as it circulates during the cutting operation moving the cuttings created thereby rearwardly in said chamber to discharge near the floor level at the rear end of the machinefand four hydraulic jacks one arranged at each corner of the machine frame and connected between said skid and said frame forr pivotally mounting the latter on said skid and for exerting Y upwardly directed forces on said frame to tilt slidable Aon its'bottom over the oor of a mine,v

a machine frame overlying and mounted on said skid, a horizontal plane cutter bar secured to the bottom or" said frame with'its forward portion extending forwardly lengthwise of the machine, the rearward'portion of said cutter bar arranged between said frame vbottom and the bottom of said skid, said frame and skid having side closure portions cooperating to provide side closures thereby to form a longitudinal substantially closed wall chamber between said skid and said frame and in which the rearward portion of said cutter bar is arranged, a cutter chain guided for circulation inY an orbital path about the margin of said cutter bar for moving the cuttings created duringthe cutting operation rearwardly through said chamber Vto discharge at'the rear end of the machine, a motor carried by said frame for drivtendingA longitudinally between the Vside jacks,

said frame to change the inclination of said'cutter bar with respect to the horizontal, said hydraulic jacks being positioned at the outerV sides of said skid and frame with said chamber exand meansfor operating said jacks to exert up-` wardly directed forces on said frame for tilting said frame in a vertical direction about a horizontal axis relative to said skid.

8. In a shortwall coal cutting machine, the combination comprising a skid slidable on its bottom over the oor of a mine, a machine frame overlying and mounted on said skid with its bottom spaced fromthe skid bottom above the latter, a horizontal plane kerf cutter secured to the bottom of said frame and extending lengthwise of the machine in the space between the frame bot.- tom and the bottom of vsaid skid for cutting a horizontal kerf near the oor level, said keriA cutter having its rearward portion disposed at the rearward end of said frame and its forward portion projecting forwardly from the front end of said frame whereby the cuttings created during the cutting operation are moved rearwardly from the kerf through the space between the frame bottom and the bottom of said skid to discharge rearwardly from the rear end of the machine, said skid and said frame having cooperating side wall portions to provide an enclosure at the sides of said space so that the cuttings conveyed rearwardly by said kerf cutter are confined in said space and conveyed rearwardly therein to discharge at the rear end of the inachine, four hydraulic jacks, one disposed at each corner of said frame and arranged between said skid and said frame for exerting upwardly directed forces on said frame selectively at different points whereby said frame may be tilted either sidewise or endwise relative to said skid to vary the inclination of said kerf cutter with respect to the horizontal, said jacks being arranged at the sides of the machine laterally outside of the enclosed space in which the cuttings are moved rearwardly by the kerf cutter with the rear jacks so located that the cuttings are discharged freely rearwardly from the machine, and means for independently controlling operation of said jacks whereby the two front jacks may be operated to tilt said frame to incline said keri- References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 545,168 Mitchell Aug. 27, 1895 1,411,932 Pray Apr. 4, 1922 1,536,795 Davis May 5, 1925' 1,632,810 Vodoz June 21, 1927k 1,801,862 Holmes Apr. 21, 1931 1,904,488 Levin Apr. 18, 1933 2,100,361 Simmons Nov. 30, 1937 2,131,178 Joy et al Sept. 27, 1938 2,295,012 Joy et al June 18, 1940 2,212,289 Farmer Aug. 20, 1940 2,261,162 Joy Nov. 4, 1941 2,283,212 Joy May 19, 1942 2,283,376 Lindgren May 19, 1942 2,283,461 Pray May 19, 1942 2,291,633 Joy Aug. 4, 1942 2,329,837 Jeirey Sept. 21, 1943 2,339,523 Sloane Jan. 18, 1944 2,547,646 Lee Apr. 3, 1951 

